title: The impact of previous tuberculosis history on T-SPOT.TB® interferon-gamma release assay results.
abstract: METHODS
  Seoul National University Bundang Hospital, a tertiary referral hospital in Korea.
  
  
  OBJECTIVE
  To evaluate whether previous tuberculosis (TB) history has a long-term effect on T-SPOT.TB® results after anti-tuberculosis treatment.
  
  
  METHODS
  We retrospectively reviewed 489 adults (age ≥18 years) who underwent T-SPOT.TB as part of their evaluation between January 2008 and July 2009.
  
  
  RESULTS
  Among 489 subjects analysed, 369 were finally included. Active TB was diagnosed in 121/369 (32.8%). T-SPOT.TB was positive in 110 (90.9%) active TB patients. Of the 248 subjects without active TB, T-SPOT.TB positivity was significantly different between the 51 patients with a previous TB history and the 197 without (84.3% vs. 26.9%, P < 0.001). The difference in T-SPOT.TB positivity between the 51 non-active TB patients with a TB history and the 121 active TB patients was not statistically significant (84.3% vs. 90.9%, P = 0.208). Among the 51 non-active TB individuals with a TB history, the mean time since anti-tuberculosis treatment was 22.7 years (range 1-59); this had no correlation with total region of difference 1 (RD1) spot-forming cells (r = -0.076, P = 0.597).
  
  
  CONCLUSIONS
  T-SPOT.TB has a limited role in the diagnosis of TB infection in individuals with a previous history of TB.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Republic of Korea.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kim
authors.forename: H I
authors.initials: HI
authors.lastname: Yoon
authors.forename: K U
authors.initials: KU
authors.lastname: Park
authors.forename: C-T
authors.initials: CT
authors.lastname: Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea; D012189:Retrospective Studies; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis* / Q000188:drug therapy; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D007371:Interferon-gamma